@judy5610 You might simply need to uninstall your current version of Sims 3 and install through the EA App instead. However, some players run into issues installing some of their packs through the App, so rather than removing all the existing program files, preserve the data for your packs, that is if you have the space.
Close the EA App and kill the EABackgroundService in the Task Manager. Right-click the Sims 3 shortcut on your desktop and select Open file location, which will land you in Bin inside the Sims 3's program files. Inside "The Sims 3" itself, you'll find one folder for each pack you've installed, labeled by type and release order. For example, Seasons was the eighth expansion released, so its folder is EP08. Copy these folders, but nothing else, to the desktop.
Next, do a clean uninstall of Sims 3:
- Put aside your Sims 3 folder in Documents\Electronic Arts and rename it to something that doesn't include the words "Sims 3."
- Download Revo Uninstaller (the free version is fine) from here.
- Launch Revo, select Sims 3 from the list, and click Uninstall.
- Once the game is uninstalled, select "Moderate" under "scanning modes," and click Scan.
- Review the list, in case there's something you want to save; otherwise, click Select All, and then Delete.
- Close Revo, and restart your computer.
You can now install the game through the EA App. If one or more packs don't install correctly, close the App and kill the background service, then copy the folders for those packs from the old Sims 3 folder you renamed to the new one, which will be here by default:
C:\Program Files\EA Games\The Sims 3
Open the App and try again to download those packs. The App should verify their presence and finalize the install rather than redownloading the content. When you're done, you can delete the folder that contained your packs.